Make regexp shorter

I have the following text: var avarb avar var varb var. What I want to do is to extract only "direct" var occurrences. The above str开发者_如何学Cing contains 3 of them.

While playing with rubular I made up the following Regexp: /\A(var)|\s(var)\s|(var)\z/. Is there a way to simplify it, in order to use var substring in regexp only once?

Try this one using word boundaries:

 /\bvar\b/

Either use Alexanders version or

/(^|\s)(var)($|\s)/       # or:
/(?:^|\s)(var)(?:$|\s)/   # (?: ) will prevent capturing 

If I understand you correctly, you can use lookaheads and lookbehinds:

/(?<=^|\s)(var)(?=$|\s)/

/\s+(var)\+/ would seem sufficient?